Injector for electric boilers



- April 28, 1931. K. o. ELDERKIN 1,802,635

INJECTOR FOR ELECTRIC BOILERS Filed Sept. 21. 1927 33 a7 29 2 MN. 3 19 2 FIBRE.

g e1 N g B INVENTOR KAR LO. ELDERKIN :50 ATI RNEYS Patented Apr. 28, 1931 UNITED STATES PATENT OFFICE KARL O. ELDERKIN, OF IROQUOIS FALLS, ONTARIO, CANADA INJECTOR FOR ELECTRIC BOILERS Application filed September 21, 1927. Serial No. 221,090.

This invention relates to new and useful improvements in water circulating devlces for electric boilers, and the main object of the invention is to provide a device which. will utilize the energy of the incoming stream of feed water, which is usually supplied under pressure, to cause a rapid circulation of water within the boiler so that the impurities in suspension and in solution in the water are evenly distributed throughout the boiler, and so that any water withdrawn therefrom will contain a much larger proportion of said impurities than in a boiler where no circulating means is employed.

In electric boilers under present operation, that is, working without a circulating jet, the hotter water containing the larger proportion of impurities in suspension, or

solution, stays at the top of the boiler and 29 the colder water tends to remain at the bot tom. In boilers of this class it is necessary to withdraw a certain quantity of said impurities from the boiler to ensure proper working of same, and also to preserve the electrodes. The said impurities are withdrawn from the boiler through drain pipes.

This drained water is hereinafter called the bleed water. It will be seen that when H drawing the bleed water from a boiler havan ing no circulating jet, a comparatively large quantity of water must be withdrawn as the colder water at the bottom of the boiler is practically pure water and contains very little impurity. This necessitates a comparaeri tively large amount of feed water being fed into the boiler to compensate for the bleed. Since it is necessary to remove a certain amount of impurities in suspension, or solution, per hour, it will be seen that if the 4-? water at the bottom of the boiler contains a greater percentage ofsaid impurities, less water need be removed and, as this hot water is sent to waste, less heat need be Wasted.

, According to my invention, I provide circulating means in the form of a jet which increases the circulation. of the water in the boiler, and therefore, a more even distribution of the impurities occurs. The jet is attached to the feed water inlet at the bottom of the boiler and is surrounded by a throat which communicates with the water at the bottom of the boiler. The feed water is forced through the jet in the usual manner and draws the water in the boiler through the throat, so that a rapid circulation of water is kept up within the boiler and a more even distribution of the impurities occurs. The water is kept at a more even temperature than is possible with a boiler having no jet. The

temperature of the bleed water from a boiler having a circulating et will, undoubtedly, be increased, but its volume will be more than proportionally decreased, so that a considerable saving in heat is obtained by using a circulating device.

In the drawings which illustrate one form of the invention Figure 1 is a part sectional side elevation of the lower part of an electric boiler, showing the water circulating device.

Figure 2 is an enlarged sectional elevation of the circulating device.

Referring more particularly to the drawings, 11 designates the cylindrical shell of an electric boiler, and 12 the bottom which is of the dished type, having upwardly turned flanges 18 secured to the shell by the rivets l4. Positioned in the centre of the boiler and held therein by any suitable means, is the electrode 15, which may be of any of the wellknown types shown in this art. The neutral plate 16 is secured to the interior of the boiler shell by any suitable attaching means. The bottom 17 of the electrode is spaced from the bottom of the boiler and in this space is mounted the water circulating device hereinafter described. Secured to the bottom of the boiler is the flanged pipe section 18, to which is secured the injector supporting casting 19, part 20 of which projects upwardly into the chamber 21 formedbetween the lower end of the boiler and said casting 19. The lower part of the casting is apertured to receive the feed water pipe 30. The upper part of the casting is recessed to receive the tapering nozzle 22, so constructed that it produces a high velocity et of water which passing through the mixing throat 23 of the injector entrains water from the bottom of the boiler through tapered recesses, or openings, 24, and forces the mixture up through the diverging funnel or tail piece 28. The nozzle is provided with flanges 25 which rest on the casting 19 and resting on said flanges are the pops or lugs 26 which project downwardly from a flange 27 formed on the lower end of the tail piece. The spaces between the lugs form the recesses or-openings 24. Set bolts29 are provided passing through the flanges of the tail piece, and the nozzle, into the casting to hold" them together. The tail piece is made. of, gradually increasing diameter as it extends upwardly into the boiler and terminatesin areinforcing beading 31, positioned a considerable distance from the lower-part of the electrodes. The partof the boiler in proximity to the injector is apertured to allow the bleed water to flow into the chamber 21 and out through the bleed' ordrain pipe 32. It will be seen that the nozzletapers inwardly from the feed water inlet towards its discharging endand projects a short distance into the boiler in proximity .to the openings 24 into the mixing throat and funnel.

, In operation water is fed into the device through the inlet pipe 30 and through the constricted nozzle to produce a high velocity jet of water which is forced into the mixing throat.

and forces it up with the feed water through the diverging funnel. This type of injectorcauses a rapid circulation of the water in the boiler and prevents accumulation or concen- ..tration of the dissolved matter near the top of the water in the boiler. As it is necessary to remove a quantity of the'dissolved matter from the boiler through the bleed pipe, it will be seen that any water taken there- .through will carry with ita quantity of said matter in much greater proportion than in a boiler whereno circulating meansis provided. The quantityof the bleed water be-- ing reduced, the feedto the boiler may be correspondingly reduced.

It will be readily understood that when using the circulating means herein described in anelectric boiler, the quantity of bleed maybe considerably reduced without excessive heat loss, and the electrodevimmersion may be kept higher to reduce the rapid wear of same, resulting in a more economical means of operating boilers of this class.

Having thus described my invention, what I claim is forming a chamber below the bottom of the boiler, a bleed pipe leadingjfrom said chan1- her, .an inlet for feed water formed in the cap andprojecting into said chamber, a nozzle'having a constricted outlet projecting into said boiler, and secured to theinlet, .a mix- The water in passing thereinto, .draws water from the bottom of the boiler ing throat secured to the inlet and surrounding the end of the nozzle, apertures formed in the mixing throat in proximity to the nozzle to allow water from the boiler to flow theret-hrough to mix with the feed water, said mixing throat communicating with a diverging funnel to direct the water towards thestop ,ot' the-boiler:

2. In an electric boiler, a Water circulating device comprising a flanged pipe section secured to the-bottom of the boiler and surrounding an aperture formed therein, a cap secured .totheipipe section to form therewith a chamber, an inlet pipe secured to the cap and projecting into said chamber, a nozzle secured to the end of said pipe, said nozzle having a constricted outlet, a diverging funnel secured'to the inlet pipe and surroundingl said nozzle, said funnel projecting into the boilerand having means formed thereinv below the nozzle to. allow-water from the boiler to pass therethrough, and also having an outlet flaring outwardly towards the top my hand.

KARL O. ELDERKINW 

